Volvo Penta — Valves and unit injectors, adjusting
Adjustments
From a Volvo Penta service manual — check it applies to your exact model before use.
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Before you start
- Incorrect valve yoke adjustment can lead to breakdown.
- If unit injector adjustment is incorrect, damage to camshaft and injectors can result.
Procedure
- Rotate engine to setting marks on camshaft and bearing cap.
- Adjust exhaust valves first.
- Adjust inlet valves.
- Adjust unit injectors.
- For each cylinder, adjust all three at same time.
- Use turning tool 9993590 to rotate engine.
- Adjust valve yoke by slackening adjusting screw clear of valve stem.
- Screw adjusting screw to valve stem plus additional hexagon side (60°).
- Tighten lock nut to 38+4 Nm.
- Adjust valve clearances and tighten lock nut to 38+4 Nm.
- For unit injector prestress, mount gauge 9998583 on dial indicator 9989876.
- Prestress dial indicator 2-3 mm.
- Screw adjusting screw until gauge bottoms and pointer stops.
- Tighten lock nut to 52+4 Nm.
- Run engine to normal temperature and idle 4-10 minutes for balancing.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Valve yoke lock nut 38+4 Nm
- Valve adjustment lock nut 38+4 Nm
- Unit injector lock nut 52+4 Nm
- Valve yoke adjusting screw additional 60°
Source: Volvo Penta service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.